Quercetin as an Agent for Protecting the Bone: A Review of the Current Evidence

Abstract

Quercetin is a flavonoid abundantly found in fruits and vegetables. It possesses a wide spectrum of biological activities, thus suggesting a role in disease prevention and health promotion. The present review aimed to uncover the bone-sparing effects of quercetin and its mechanism of action. Animal studies have found that the action of quercetin on bone is largely protective, with a small number of studies reporting negative outcomes. Quercetin was shown to inhibit RANKL-mediated osteoclastogenesis, osteoblast apoptosis, oxidative stress and inflammatory response while promoting osteogenesis, angiogenesis, antioxidant expression, adipocyte apoptosis and osteoclast apoptosis. The possible underlying mechanisms involved are regulation of Wnt, NF-κB, Nrf2, SMAD-dependent, and intrinsic and extrinsic apoptotic pathways. On the other hand, quercetin was shown to exert complex and competing actions on the MAPK signalling pathway to orchestrate bone metabolism, resulting in both stimulatory and inhibitory effects on bone in parallel. The overall interaction is believed to result in a positive effect on bone. Considering the important contributions of quercetin in regulating bone homeostasis, it may be considered an economical and promising agent for improving bone health. The documented preclinical findings await further validation from human clinical trials.

The relationship between healthy lifestyles and bone health

“…[ 26 ] However, an increasing number of studies are proving that fruits have a positive effect on bone health because of their antioxidative contents. [ 27 ] Overall, many supplementations are widely recognized and used for bone health benefits, but more research is needed to confirm the optimal form and dosage of dietary supplements, as well as their potential hazards.…”

Effect of Quercetin 3-O-β-D-Galactopyranoside on the Adipogenic and Osteoblastogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stromal Cells

“…It has been shown that quercetin has a beneficial effect on bone resorption, osteogenic differentiation and overall bone repair mechanisms [19,20]. Some reports displayed that quercetin treatment enhanced the osteoblastogenic differentiation of pre-osteoblasts through increased ALP activity and mineralization [21].…”

Therapeutic Single Compounds for Osteoarthritis Treatment

“…Quercetin is widely present in the flowers, leaves, and fruits of plants. Its pharmacological effects have been extensively studied, including its antioxidant, anticancer, anti-inflammatory, antibacterial, and antiviral activities [ 68 , 69 ].…”